It is known from U.S. Pat. No. 3,812,668, for example, to manufacture yarn from continuous filaments which will have a slub effect along the length of the yarn. Two ends of yarn are fed, one at a greater relative velocity, through a turbulence chamber into which a gas is injected to intermingle the filaments of the two ends together. Described therein are two techniques for forming the slub with the yarn end fed at a greater relative velocity--by allowing the gas to be injected into the chamber in the direction opposite the yarn travel, and by overfeeding the yarn end by means of a fluid jet prior to intertanglement with a second jet device.
While the techniques discussed above are said to produce tension-stable, slub-effect yarns, the present invention has advantages in processing performance and economics.